Roundabouts. Roundabouts shall be adopted, as appropriate, for intersections with high turning or crossing traffic. They are also desirable for lower turning flows: • at the start of a bypass • to highlight the change of road class and design speed • to replace a priority crossroad • to define the start and end of an urbanized section The following roundabout types shall not be adopted without strong justifications: • Mini-roundabouts • Roundabouts on Class I roads with six or more lanes, unless they are signalized • Roundabouts with oval or irregular central islands The design of roundabouts shall adhere to strict safety principles including: • Limitation of entry path radius • Avoidance of drivers seeing through the roundabout on a straight alignment • Adequate signs and speed reduction measures on the approach • Appropriate visibility at entries and within the roundabout • Passive safety for the central island, splitter islands and the roadside Preference should be given to single lane or 2-lane compact roundabouts wherever capacity permits. Addition of traffic lanes at the entrance to a roundabout should not be adopted unless this practice is already widely in operation without problem. If there are pedestrians and slow traffic at the roundabout, the following precautions shall apply: • Preference for single lane compact roundabout • Preference for single lane exit at 2-lane roundabouts • Provision of pedestrian footpaths and appropriate crossing facilities • Provision of separate slow vehicle tracks and appropriate crossing facilities • Provision of traffic calming measures Signalized Intersections Signalized intersections shall be adopted, as appropriate, for intersections with high turning or crossing traffic. They are also appropriate with any turning flows on multi-lane roads and to facilitate pedestrians or slow vehicles to cross a road. Traffic signals shall have 3-aspect displays in red, amber and green colors. Pedestrian signals shall be in red and green color. Flashing display may be adopted according to national standard. Cycle time of signalized intersections shall normally be limited to 120 seconds and preferably not more than 100 seconds. Adequate intergreen period shall be provided to separate green signal displays between conflicting traffic streams, pedestrians or slow vehicles. Signalized pedestrian crossings shall be positively controlled with pedestrian signals. The overall green period on pedestrian signals shall be adequate for pedestrians to ...
Roundabouts. Consultant shall evaluate Ashland intersections and make recommendations for those that may be appropriate for roundabouts, including mini-roundabouts in gridded neighborhoods. Consultant shall identify specific safety and comfort measures for bicyclists and pedestrians negotiating roundabouts.
Roundabouts. All roundabouts shall be concrete and designed in accordance with chapter 915 of the WSDOT design manual.
Roundabouts. The Town and DRH shall consult in good faith about standards for roundabouts, which are not covered in the Standards Manual.
